1. Field of the Invention
This invention relates to the production of cyclohexanol by the catalytic hydrogenation of phenol.
2. Description of the Prior Art
The manufacture of cyclohexanol by catalytic hydrogenation of phenol is known, as shown in U.S. Pat. No. 3,998,884 to Gibson, issue date Dec. 21, 1976, and U.S. Pat. No. 2,794,056 to Winstrom, issue date May 28, 1957. Phenol is subjected to catalytic hydrogenation under conditions known in the art which effect conversion of phenol substantially to cyclohexanol. Cyclohexanone is a byproduct in this process, which must be removed by distillation to meet product specifications in the merchant market. The more cyclohexanone to be removed, the higher the energy costs and the smaller the yield of cyclohexanol meeting required product specifications. In a typical batch process, during the final stages of phenol conversion to cyclohexanol, the amount of cyclohexanone produced may rise to 0.2 to 0.3 weight percent, a level that is in excess of most commercial product specifications that provide for a maximum level of cyclohexanone in cyclohexanol.
The need exists to provide an efficient process to increase the yield of cyclohexanol meeting required product specifications regarding the maximum levels of cyclohexanone permitted.